DOI: 10.1016/j.epsl.2020.116296
论文题名: Pūhāhonu: Earth's biggest and hottest shield volcano
作者: Garcia M.O. ; Tree J.P. ; Wessel P. ; Smith J.R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 542 语种: 英语
中文关键词: gravity
; Hawaii
; magma temperature
; olivine
; solitary wave
; volume
英文关键词: Basalt
; Melting point
; Silicate minerals
; Solitons
; Cenozoic
; Hawaiian Islands
; Mauna Loa
; Olivine phenocryst
; Partial melting
; Propagation rate
; Volume calculation
; Volume flux
; Volcanoes
; basalt
; high temperature
; mantle source
; partial melting
; petrogenesis
; petrology
; volcanic eruption
; volcanism
; volcanology
; Hawaii [(ISL) Hawaiian Islands]
; Hawaii [United States]
; Hawaiian Islands
; Hawaiian Ridge
; Mauna Loa
; Pacific Ocean
英文摘要: New bathymetric and gravity mapping, refined volume calculations and petrologic analyses show that the Hawaiian volcano Pūhāhonu is the largest and hottest shield volcano on Earth. This ∼12.5-14.1 Ma volcano in the northwest Hawaiian Ridge (NWHR) is twice the size of Mauna Loa volcano (148 ± 29 vs. 74.0×103km3), which was assumed to be not only the largest Hawaiian volcano but also the largest known shield volcano. We considered four testable mechanisms to increase magma production, including 1) thinner lithosphere, 2) slower propagation rate, 3) more fertile source, and 4) hotter mantle. The first three of these have been ruled out. The lithosphere was old (∼88 Myrs) when Pūhāhonu was formed, and thus, too thick and cold to allow for greater extents of partial melting. The propagation rate was relatively fast when it erupted (87 km/Myr), so this is another unlikely reason. Source fertility was Kea-like and no more fertile than for other much smaller NWHR volcanoes. A hotter mantle remains the best mechanism to produce the large magma volumes and is consistent with the high forsteritic olivine phenocryst compositions (up to 91.8%) and the calculated high percent of melting (24%). Thus, the gargantuan size of Pūhāhonu reflects its high melting temperature, the highest reported for any Cenozoic basalt. A solitary wave within the Hawaiian plume is the probable cause of Pūhāhonu's higher melting temperature and the resulting increased volume flux given the absence of a more fertile source for Pūhāhonu basalts, as found for many basalts from the Hawaiian Islands. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164974
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth Sciences, University of Hawai‘i at Mānoa, Honolulu, HI 96822, United States; Department of Oceanography, University of Hawai‘i at Mānoa, Honolulu, HI 96822, United States
Recommended Citation:
Garcia M.O.,Tree J.P.,Wessel P.,et al. Pūhāhonu: Earth's biggest and hottest shield volcano[J]. Earth and Planetary Science Letters,2020-01-01,542